Hydraulic pump



E, STANLEY May 24, 1932.

HYDRAULI C PUMP Filed April 25. 1927 I; Sheets-Sheet l J'zzveg/oz {@flfforneys E. STANLEY HYDRAULIQPUMP May 24, 1932. I

Filed April 26. 19 3 Sheets-Sheet 2 E. STANLEY May 24, 1932.

HYDRAULIC PUMP Filed April 26. 1 27 (Q Sheets-Sheet 5.

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Patented May 24, l932 PATENT oFFIcE ENDS STANLEY, OF HACKENSACK, MINNESOTA.

mmmuuc Prmr Application filed April 26,

The object of my invention is to provide a hydraulic pump of simple, durable and inexpensive construction, wl1ich is particularly adapted to be used in hydraulic transmission devices for automobiles, and toprovide improved means for circulating the operating fluid under pressure, whereby the speed ratio between the driving shaft of the engine and the traction wheels of the automobile may ,be automatically varied to meet the various load conditions, so that the engine may be maintained at a comparatively constant speed and efiiciently operated.

A further object is to provide in a hydraulic pump of class above described improved means whereby an auxiliary supply of fluid may be carried and automatically fed to the transmission system for replacing the loss of fluid due to leakage.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which: t

Figure 1 is a plan view of an automobile frame showing the manner in which my improved hydraulic transmission is applied thcreto.

Figure 2 is a detail sectional view taken on the line 22 of Figure 4.

Figure 3 is a detail'sectional view taken on the line 3+3 of Figure 8.

Figure 4 is a side elevation of the pump used in my improved hydraulic transmission, portions of the side being broken away to show the interior construction, said broken away portion being taken substantially on the line 4-4 of Figure 5.

Figure 5 is a detail sectional view taken on the line 55 of Figure 4.

Figure 6 is a detail sectional view taken on the line 6 6 of Figure 4.

Figure 7 is a rear view of the the reverse valves.

Figure 8 is an enlarged, detail. sectional view taken on the line 8-8 of Figure 4.

Figure 9 is a detail sectional view taken on the line 9-9 of Figure 4.

pump and 1927. Serial No. 186,701.

Figure 10 is a detail sectional view taken on the line 10-10 of Figure 7.

The numeral 10 indicates the main frame of an automobile having at its rear end traction wheels 11 which are supported on suitable axles rotatively mounted in the axle housing. Each end of the axle housing 13 is provided with a motor casing 14 having a hydraulic motor for driving the corresponding wheels 11, the operating fluid being fed to the motor by pipes 24 and 25.

For imparting the desired movement and pressure to the fluid within the pipes 24, is provided-an engine 26 of the kind in general use in automobiles, having a rearwardly extending drive shaft 27. Mounted on the shaft 27 is my improved pump 28 which comprises a cylindrical wall 29 having at each edge outwardly projecting flanges 30. An end plate 31 is secured to one of the flanges 30 and is provided with a hub 32 in which the shaft27 is rotatively mounted. The cyl inder casing 29 is rigidly secured to the automobile frame by means of a suitable cross bar 33. Secured to the opposite side of the casing 29 is a plate 34. The inner faces of the plates 31 and 34, together with the inner face of the casing 29, are machined smooth and designed to receive a rotatively mounted pump head 35, which is cylindrical in formation. The periphery of the head 35 is provided with a series of transversely arranged recesses 36. Adjacent to the forward edge of each of the recesses 36 is pivotally mounted what I shall term a pressure blade 37 said blade having its central portion bulged to add weight to the same; The outer edge of the blade 37 is formed with a cylindrical bar 38 for the purpose of engaging the inner surface of the casing 29, and designed to provide a bearing member which may be replaced when so desired.

It will be seen by referring to Figure 5 that the wall of the casing 29 is formed somewhat elliptical, the vertical portions of said wall being caused to engage the periphery ofthe pump head 35, while the top and bottom portions of said wall are spaced apart from said pump head a considerable distance. A portion of the vertical walls of said casing is formed concentrically with the pump head through a distance equal to the space between two of the recesses 36, while an equal portion of the top and bottom walls of said casing is formed concentrically with thecylinder head. The top and bottom concentric portions connect with the vertical concentric portions by curved inclined portions 39. If the head 35 is rotated within the casing 29, the bars 38 of the blades 37 will be thrown out against the inner surface of the casing wall by centrifugal force, the member 38 being caused to follow the contour of said surface. The width of eachof the blades 37 is such that at no time are the front faces of the blades absolutely in a radial plane from the center of the head 35, the faces of said blades always being inclined backwardly from said radial plane, so that any wear that might take place between the member 38 and the outer wall of the casing will be automatically taken up. The blades 37 are adapted to be moved K into the recesses 36 as they move past the vertical concentric portions of the walls.

It will further be seen that the space between the head 35 and the casing 29 is divided into upper and lower cylinder compartments, each of which is independent of the other. The plate 34 is provided with a pair of intake openings or slots 40 communicating with the inlet end of said compartments. The plate 34 is also provided with a series of outlet openings 41 communicating with the opposite end of said compartments. Each of the openings 41 is provided with a valve 42, each of said valves having a stem 43 slidably mounted in an inwardly extending sleeve 44 detachably mounted in a plate 45 spaced a distance from the plate 34, so that an outlet chamber 46 is provided. said chamber being clearly illustrated in Figure ,6. The outlet openings 41 are located in that portion of the plate 34 adjacent to the inclined wall member 39. The space between the plates 34 and 45 is divided into compression chambers 47 and an auxiliary supply chamber 48. The outlet chamber 46 and the compression chamber 47 of each set of chambers are in communication with each other. The lower end of the auxiliary chamber 48 communicates with the upper one of the intake slots 40, while the lower one of the ini take slots 40 is in communication with the 55 auxiliary supply chamber 48 by means of a narrow passage 49.

Assuming that the auxiliary chamber 48, together with the chambers 46 and 47 and the cylinder chambers, are filled with a fluid such as oil, and that the pump head 35 is rotated in a counter-clockwise direction, then it will be seen that the blades 38 will be thrown outwardly following the contour of the casing 29, and the said blades 37 acting as pistons, causing oil to enter the pump chambers through the openings 40 and to be expelled through the openings 41.

Thus it will be seen that pressure will be created in the outlet chambers 46 by the rotation of the pump head.

Secured to the plate 45 is a pair of valve casings 50, each of which is provided with a rotatively mounted valve 51. Each of the valve casings 50 is provided with an outlet opening 52 and an intake opening 53. The outlet opening 52 communicates with the compression chamber 47, and one of the inlet openings 53 communicates with the lower end of the auxiliary chamber 48, and the other opening 53 communicates with the lower end of the passage 49. Each of the casings 50 is also provided ,with an opening 54 in alinement with the opening 52 and an opening 56 in alinement with the opening 53. The opening 56 is designed to receive the pipe 25 of the motor in one of the wheels 11, and the opening 54 is designed to receive the pipe 24 of the opposite motor. in the manner clearly illustrated in Figure 1, so that the circulation of oil through the top cylinder chamber will be maintained through ,one of the motors, while the circulation of oil from the bottom of the cylinder chamber will be in operative relation with the other one of said motors. The valve 50 is provided with an opening 57 designed to connect the openings 54 and 52 when the valve is in one position of its movement, and also provided with an opening 58 for connecting the openings 56 and 53 when the said valve is in the same position. The valve 51 is also provided with a passage 59 for connecting the opening 56 with the opening 52 when the valve is in another position of its movement. The valve 51 is also provided with a passage 60 for connecting the openings 54 and 53 when the valve is in the last said position of its movement.

By this arrangement it will be seen that oil mav be made to travel through the pipes 24 and 25 in reverse directions by simply changing the position of the valve 51, while the circulation of oil through the pump chambers is always in the same direction. The valve 51 provides means whereby the motors may be reversed, and consequently the direction of the travel of the automobile may be reversed.

It will be seen by referring to Figure 9 that the angular space between the passages 57, 59 and 60 is greater than the diameter of the horizontal openings of the valve casing, so that if the valve 51 is rotated through an angle of substantially 45, then the inlet and outlet passages will beclosed and no circulation will be permitted through the pipes 24 and 25, and consequently no circulation will be permitted in the motors. By this arrangement the valves 51 may be made to serve the purpose of applying brakes to the traction wheels.

By-pass pipes 69 are provided between the upper and lower cylinder chambers, each of said pipes being provided with a valve casing 70 having a spring actuated check valve 71. Each of said valves is provided with a stem 72 designed to be operatively connected with a bell. crank lever 73, by means of which the valve may be lifted from its seat by manually controlled means. When the said valves 71 are lifted from their seats, oil from one of the chambers will be permitted to pass to the other chamber, which will cause the pressure of the pipes 24 and 25 to be reduced, in such a manner that by proper manipulation of the said valves 71, the pressure applied to the motors may be varied at the will of the operator, to permit the automobile to coast if so desired. The "alves 71 also provide a by-pass between the upper and lower cylinder chamberswhen the valve 50 has been moved to its braking position, and

at a time when-the engine is running at high velocity.

The manner in which the speed ratio'between the engine and the traction wheels is automatically varied is as follows:

. Assuming that the engine speed is constant, it will then be seen that the speed of the pump head will also be constant, and that the members 38 of the blades 37 will be caused to follow the contour of the casing 29 due to the centrifugal force, and oil will be caused to circulate through the pipes 24 and 25, if the valve 51 is moved to an open position, and the traction wheels will be caused to rotate in unison therewith,

and at a predetermined speed ratio between the engine and the traction Wheels, said speed ratio depending upon the dimensions of the pump compared with the dimensions of the motor.

Further assuming that the resistance to the advance of the automobile is such as to create a pressure in the cylinder chambers to just balance the centrifugal action of the blades 37 when they are moved to their outer position of movement, or to that position which is nearest the radial plane, then the volume of oil delivered by the pump will be in proportion to the cross sectional area of the larger portion of the cylinder multiplied by the velocity, or in other words, the pump will be operated at its maximum volume, in which case the automobile will be advanced over the ground surface in what is commonly known as high gear.

Assuming, however, that the resistance of the automobile is materially increased, such as when climbing a hill, then the back pressure in the cylinder chambers will also be increased, which will overcome the forward pressure created by the centrifugal action of the blades 37 to a certain extent, and permit the blades operating in the concentric portion of-the casing to be inclined rearwardly a slight distance, permitting a portion of the oil to move past the outer edge of the blade.

Assuming that the blade has been moved rearwardly to the position where its outer edge will follow the dotted line 7 4, shown in Figure 8. then it will be seen that the outer edge of the blade 37 will-engage the inclined surface 39 at a point 75. When the blade has engaged thisportion of the inclined surface, it will be seen that the active area of the blade 37 has been considerably reduced, and consequently the volume of oil delivered by the pump will also have been reduced, causing a reduction of the speed ofthe traction wheels. It will also be seen that the inclination of the front face of the blade 37 has been increased relative to the radial plane, or in other words, the body portion of the blade has been brought closer to the center of the rotating head, and the center of gravity of the blade has been brought to a point nearer right angles to the radial plane, which will greatly increase the pressure between .76 is equal to the area of one end of the chamber between two adjacent pressure blades multiplied by the length of the pressure blade.

This pressure will continueto increase until the resistance of the automobile has been overcome, at which time the pressure will be maintained substantially constant due to the action of the oil and airwithin the compression chamber 47,-and further due to thefact that the momentum of the automobile, after it has been brought to the lower speed ratio.

is practically constant. The operating pressure in the system is the pressure obtained after the blades have reached the point 75, or the mean pressure exerted by the blades while in contact with the inclined surface 39. The volume of fluid delivered to the motors is the mean volume delivered by the blades between the points 75 and 76. The variation from the mean volume and pressure is taken care of in the compression chamber 47. That is, when the blade 37 is at the point 75, oil will be delivered to the compression chamber, and when the blade is at the point 76, oil will be delivered from the compression chamber to the motors, in addition to what is delivered by the blade 37 when at the point 76, so that a constant volume of oil is delivered to the motors.

It will readily be seen that the pressure within the chamber 4;7'will vary as the oil is delivered to or from said chamber. This variation in pressure, however, can be greatly reduced by increasing the size of the air chamber in comparison to the volume of oil delivered thereto, as the pressure in said chamber is in direct proportion to the increase or decrease in volume. In the drawings, I have illustrated a comparatively small compression chamber for the sake of simplicity. In actual practice the air chambers should be several times larger than the variation in the volume of oil delivered to and from said compression chambers.

It will further be seen that when the blades 37 are located in the positions 75 and 76, the chamber A, between said blades, is smaller than the chamber B, back of said blades, and that the pressure in the chamber A is greater than in the chamber B, and that unless the valves are provided, oil would flow from the chamber A to thechamber B, and no increased pressure would be imparted to the motors other than that when the automobile is running in high gear.

The intake openings of the cylinder chambers are in communication with the auxiliary chamber 48, which is filled with oil and maintained at atmospheric pressure, and a vent opening 77 is provided for that purpose. Any leakage from one cylinder to the other will be compensated for in the auxiliary chamber. Said auxiliary chamber is also designed to give and take the variation in volume created in the compression chambers l7.

The operation just described has been under the assumption that the engine speed is normal, and the automobile is being advanced at various speed ratios depending upon the resistance of the advance of the automobile over the ground surface.

Assuming that the automobile is standing still and that the speed of the engine is being accelerated from zero to a normal speed, then it will be seen that as the engine is started no appreciable pressure will be created, due to the fact that the centrifugal action of the blades 37 is substantially zero, and the oil .simply moving past the outer edges of the blades, but as the speed of the engine is accelerated, the centrifugal action of the blades will be increased and the pressure in the transmission will also be increased, giving a steady starting moment to the automobile.

From the foregoing description it will be seen that each of the traction wheels might be considered as being operated in unison, inasmuch as the pressure in each of the cylinder chambers is created from a single pump head. It will be seen, however that if the resistance of one of the traction wheels is greater than the other, then a differentiating speed may be provided, inasmuch as a certain portion of the oil will move'past the blades in one of the cylinder chambers, thereby serving the purpose of the ordinary differential, and at the same time eliminating practically all of the skidding tendency of the automobile, due to the fact that it is necessary to exert considerably more resistance on one wheel than the other before the differentiating action takes place. The natural tendency of the automobile is to advance in a straight line.

I claim as my invention:

1. A hydraulic pump comprising a substantially oblong casing, a cylinder piston rotatively mounted within said casing, said piston being designed to fit the contracted portions of said casing to divide the casing into a pair of cylinder chambers, the periphery of said piston being provided with a series of transversely arranged grooves, apressure blade for each of said grooves, the forward edge of each of said pressure bladesbeing pivotally connected to the forward edge of said groove and designed to swing outwardly by centrifugal force with their free.

edges engaging the inner face of said casing, an inlet opening for each of said cylinder chambers, a series of outlet openings in the walls of said cylinder occupying an area adjacent to the discharge end of the cylinder chamber and extending rearwardly a distance equal to or greater than the distance between two adjacent pressure blades, each of said outlet'openings being provided with a spring actuated valve, an outlet chamber communicating with each set'of outlet openings, and

an auxiliary supply chamber communicating with both of said inlet openings.

2. A hydraulic pump comprising a substantially oblong casing, a cylinder piston rotatively mounted within said casing, said piston being designed to fit contracted portions of said casing to divide it into a pair of cylinder chambers, the periphery of said PlS-r ton being provided with a series of transverselyarranged grooves, a pressure blade for each of said grooves, the forward edge of each of said pressure blades being pivotally connected to the forward edge of said groove and designed to swing outwardly by centrifugal force, the spacing of the grooves in said piston being such that a number of pressure blades may simultaneously engage the inclined surface of said oblong cylinder, a se ries of outlet openings arranged to simultaneously communicate with a number of the spaces between adjacent pressure blades, a spring actuated valve for each of said openings, and a compression chamber communicating with each set of outlet openings.

' ENOS STANLEY. 

